Low sensitivity of invasive tests for the detection of Helicobacter pylori infection in patients with bleeding ulcer.

Background: A high false negative rate for antral infection with Helicobacter pylori when assessed by rapid urease test has recently been reported in patients with bleeding ulcer. This result could partly explain the differing prevalence of H. pylori infection in bleeding and non-bleeding ulcers.

Aims: To evaluate the accuracy of a rapid urease test (UT), histology and culture for detection of H. pylori in antral biopsies from acute bleeding peptic ulcer patients using a serological test as reference.

Patients And Methods: All consecutive patients with active bleeding gastric or duodenal ulcer at endoscopic examination admitted in six university hospitals in France were considered for inclusion. Five antral biopsies were taken during the diagnostic endoscopy for UT, culture and histology. A blood sample was taken for H. pylori serology.

Results: One hundred and eighty one patients were included and 129 (71%) had a positive serology. The sensitivity of UT, histology and culture for detection of H. pylori infection were 41%, 33% and 34%, respectively. The sensitivity and specificity of the combination of the three invasive tests were 48.8% (95% CI: 40.2-57.4) and 90.6% (95% CI: 82. 6-99) respectively. In the 52 serologically negative patients, only 5 had at least one invasive positive test. The sensitivity of the invasive tests decreased significantly with age but was not influenced by NSAIDs intake. Of 80 patients with a positive serological test and negative histological evaluation for H. pylori, chronic antral inflammation was found in 70 patients (87%). In 46 patients with both negative serological test and H. pylori negative test according to histology, only 13 (28%) had chronic antral inflammation.

Conclusions: The sensitivity of invasive tests for detection of H. pylori is low during acute ulcer bleeding, and they should be used with caution in this condition. A serological test is recommended to identify patients with H. pylori infection in spite of negative invasive tests.